Does progesterone show neuroprotective effects on traumatic brain injury through increasing phosphorylation of Akt in the hippocampus

• Published in: Neural regeneration research 2014-11, Vol.9 (21), p.1891-1896
• Main Authors: Garling, Richard Justin, Watts, Lora Talley, Sprague, Shane, Fletcher, Lauren, Jimenez, David F, Digicaylioglu, Murat
• Format: Article
• Language: English
• Subjects: Akt; Apoptosis; Brain; Cellular signal transduction; Control; Immunoglobulins; Injuries; Kinases; Laboratories; Phosphorylation; Physiological aspects; Progesterone; Proteins; Research and Report; Traumatic brain injury; 保护作用; 信号传导途径; 创伤性脑损伤; 显示; 海马; 磷酸化位点; 黄体酮
• ISSN: 1673-5374; 1876-7958
• DOI: 10.4103/1673-5374.145355

There are currently no federally approved neuroprotective agents to treat traumatic brain injury. Progesterone, a hydrophobic steroid hormone, has been shown in recent studies to exhibit neu-roprotective effects in controlled cortical impact rat models. Akt is a protein kinase known to play a role in cell signaling pathways that reduce edema, inlfammation, apoptosis, and promote cell growth in the brain. This study aims to determine if progesterone modulates the phosphor-ylation of Aktvia its threonine 308 phosphorylation site. Phosphorylation at the threonine 308 site is one of several sites responsible for activating Akt and enabling the protein kinase to carry out its neuroprotective effects. To assess the effects of progesterone on Akt phosphorylation, C57BL/6 mice were treated with progesterone （8 mg/kg） at 1 （intraperitonally）, 6, 24, and 48 hours （subcutaneously） post closed-skull traumatic brain injury. The hippocampus was harvest-ed at 72 hours post injury and prepared for western blot analysis. Traumatic brain injury caused a signiifcant decrease in Akt phosphorylation compared to sham operation. However, mice treat-ed with progesterone following traumatic brain injury had an increase in phosphorylation of Akt compared to traumatic brain injury vehicle. Our ifndings suggest that progesterone is a viable treatment option for activating neuroprotective pathways after traumatic brain injury.